In the lab

By Jim DiPeso

Oct 01, 2000

Zeolites fuel-up at space station

National Aeronautics and Space Administration (NASA) and industry are funding research to study crystals with the potential to reduce pollution associated with gasoline production and other petroleum products. These crystals are called zeolites and have a network of interconnected tunnels and cages, much like a honeycomb.

Virtually all the world's gasoline is produced using zeolites and they are used in cars where improved zeolite crystals would mean that more gasoline could be produced from a barrel of oil. To facilitate this goal, NASA has helped industry grow zeolite crystals on three NASA Space Shuttle missions since 1992. They are to be grown on a Shuttle mission again next year and on the International Space Station, the first permanent research laboratory in space.

NASA's Commercial Space Center at Northeastern University is working both to help industry improve petroleum fuel refining and to develop new fuels that are cleaner. Hydrogen is one of the candidate fuels being investigated. Companies have designed engines that burn hydrogen, but scientists must find a way to store and transport it safely and easily.

"Our experiments in space have shown that larger and better quality crystals can be grown in microgravity," said former Space Shuttle crewmember Dr. Albert Sacco Jr., director of the Center for Advanced Microgravity Materials Processing, a NASA Commercial Space Center at Northeastern University in Boston.

The problem with zeolite crystals produced on Earth is that they are extremely small -- roughly two to eight microns, about the size of microscopic bacteria. To better define the structures of zeolites, scientists need to grow crystals that are 200 to 1000 times larger.

"Data from space experiments are helping us grow better zeolite crystals on Earth," said Sacco. "Industry wants to fine-tune the structure of zeolites to get more gasoline out of a barrel of oil during the refining process. Theoretically, this could lead to less dependence on foreign oil."

Additionally Saccoo said, "Zeolites can store quite a bit of hydrogen. We need to find out how to store enough hydrogen so that it can be used in a car fuel tank at normal operating temperatures and pressures. One way to do this would be to make zeolites or zeo-type materials that can store hydrogen much like a liquid in a bottle."

Hydrogen is the most abundant element in the universe, and it's pollution free. Sacco predicts hydrogen fuel will be a "leapfrog technology" that changes the way we live - much like the revolutionary change when the world moved from coal to petroleum as its primary fuel.

"In microgravity, materials come together more slowly, allowing zeolite crystals to form larger and with better order," said Sacco, who worked as a payload specialist and grew zeolites aboard the Space Shuttle on the STS-73 mission in 1995. "These larger, more perfectly formed space-grown crystals tell us more about the way the crystal is made and how it works. If we can find a way to store hydrogen safely and inexpensively, in 10 to 15 years, you'll see America turning from gasoline to hydrogen as the main fuel source," said Sacco.

While most of their 1999 research focused on zeolites, Sacco and his research team at the Commercial Space Center in Boston are also studying how space and microgravity can be used to improve other materials.

"Through Commercial Space Centers like ours, NASA will help industry take advantage of a national resource the International Space Station -- the most sophisticated laboratory to ever be put in orbit," Sacco said.

One's trash is another's treasure

Researchers at Memorial Sloan-Kettering Cancer Center in New York may have found a new form of therapy for cancer patients ? enough to treat up to 100,000 cancer patients a year.

The key to this breakthrough comes from middle-aged waste. For more than 40 years, Oak Ridge National Laboratory has housed weapons-grade uranium-233, the producer of bismuth-213 ? a potent isotope that can kill leukemia cells without harming healthy cells.

"It is kind of like a little bomb going off that you can target right to that cancer cell," the lab's program manager Jim Rushton said.

Oakridge's supply of uranium-233 was manufactured in the '50s and '60s at the government's weapons fuel production plants in South Carolina and Washington state. It was intended to fuel commercial nuclear plants but the need for this alternative fuel never developed.

Bismuth-213 can be obtained in what physicists describe as a decay chain from uranium-233. First, thorium-229 is extracted, then actinium-225 is taken from that and then the bismuth is extracted from the actinium. The search for thorium led to the uranium-233 stockpile in Oak Ridge. Bismuth-213 has a 46-minute half-life, making it perfect for injecting into patients because it dissipates quickly, but is difficult to obtain.

Last year, initial human tests were completed revealing the therapy to be safe and effective. Leukemia cells were eliminated in the blood stream and reduced in the bone marrow of 13 of the 18 patients taking part in the research. The innovation is called "alpha particle immunotherapy."

The isotope bismuth-213 was attached to an antibody designed to carry the alpha-emitting isotope to the cancer. "The process of carrying the radiation dose straight to the diseased cell is an innovative treatment certainly worth pursuing," said Dr. Jorge Carrasquillo, deputy chief of nuclear medicine at the National Institute of Health.

The researchers don't envision bismuth therapy replacing chemotherapy or surgery. Instead, they see it as a possible method to clean up residual cancer cells that stay behind after primary treatments.

"The majority of patients go into remission with chemotherapy, but they relapse because of the residual cells. That's where we think the bismuth is going to be particularly useful," one of the researchers, Dr. Joseph Jurcic said.

A second phase of research by Sloan-Kettering is planned for the Fall under the watch of the National Cancer Institute. The therapy's effectiveness will be tested on 35 to 40 patients for up to three years.

Although the bismuth extraction will not actually diminish the amount of uranium-233 waste, it gives the waste more value as a key to cancer treatment.

For more information, visit the Memorial Sloan-Kettering Cancer Center online at www.mskcc.org.

Caught on film - saving the manatee

Any species of animal living in the wild will suffer losses from natural causes and can usually overcome those losses, but the manatee population must also deal with mortalities caused by human-related factors.

One of the leading natural causes of manatee deaths is attributed to cold temperatures. Death from exposure to cold is an unfortunate by-product of the fact that some manatees are living at the northern-most extreme of their geographic range.

Manatees most affected by cold exposure are approximately two to three years old. These young manatees often have not faced a winter without their mother guiding them. Larger, more experienced adults are more aware of the location of warm water areas and are better able to monitor temperature cues and travel accordingly.

A multi-year investigation addressing a variety of questions about the cold-weather habitats of the endangered Florida manatee is being undertaken by the Physiological Ecology and Bioenergetics Laboratory of Texas A&M University and the Hubbs-Sea World Research Institute with the help of Film Technologies International (FTI). FTI's window film (usually used to provide protection against dangerous threats and accidental injury by helping to hold glass shards together in the window frame in the event the glass is shattered) was used in laboratory research methods to help discover manatee's metabolism.

"To better understand how manatees deal with cold, we have measured the metabolic capacities of a number of manatees," head of the research project, Dr. Graham Worthy of Texas A&M said. "Adult manatees have very low metabolic rates. This is one of the reasons they cannot cope with cold temperatures and is why they congregate in specific warm water areas during winter months."

To calculate a manatee's metabolic rate, Dr. Worthy and his team measure its rate of oxygen consumption by covering a tank of water with 100-square feet of 12-mil GLASS-GARD security film donated by FTI -- an alternative to heavy Plexiglas.

"The cover basically acts like a giant facemask. Fresh air is constantly pulled through the covered area of the tank, the animal breathes in oxygen and exhales carbon dioxide, thereby changing the concentrations in the airstream. We monitor those changes using sensitive measuring equipment," Dr. Worthy said. "By modifying water temperatures, we can then quantify the animal's ability to deal with a range of water temperatures."

Worthy's research is an attempt to elucidate the capabilities of manatees to withstand normal seasonal variation in their environment and to more appropriately define suitable criteria for their husbandry in captivity.

For further information on manatee research, check out the Texas A&M University at Galveston Department of Marine Biology Website at www.marinebiology.edu.

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This article appeared in Environmental Protection, Volume 11, Number 10, October 2000, Page 11.

This article originally appeared in the 10/01/2000 issue of Environmental Protection.